Comb copolymers with defined side chains and process for their manufacture

ABSTRACT

The present invention relates to the modification of copolymers, in particular of grafted copolymers into comb copolymers. The modification comprises the steps (i) of controlled radical polymerization of a polymer or copolymer bearing a epoxide group at one end resulting from the initiation step, and (ii) a heating step of the polymer prepared under (i) and a copolymer bearing a functional group either in the backbone or attached to a side chain, which is able to react with the epxide group. The result is a comb copolymer with well controlled chain length of the grafted side arms expressed for example by a low polydispersity.

The present invention relates to the modification of copolymers, inparticular of grafted copolymers into comb copolymers. The modificationcomprises the steps (i) of controlled radical polymerization of apolymer or copolymer bearing an epoxide group at one end resulting fromthe initiation step, and (ii) a heating step of the polymer preparedunder (i) and a copolymer bearing a functional group either in thebackbone or attached to a side chain, which is able to react with theepxide group. The result is a comb copolymer with well controlled chainlength of the grafted side arms expressed for example by a lowpolydispersity. Further aspects of the invention are a composition ofthe polymers (i) and (ii), a comb copolymer obtainable according to theprocess and the use of such a comb copolymer as for examplecompatibilizer, impact modifier or barrier material.

Increasing activities have been directed towards chemical modificationsof existing polymers in order to obtain functional and/or engineered newmaterials. Chemical modifications of existing polymers are important forat least two reasons: 1. They can be an inexpensive and rapid way ofobtaining new polymers without having to search for new monomers. 2.They may be the only way to synthesize polymers with the intended newcharacteristics.

A heating process is often a melt processing step, such as for examplereactive extrusion. It is a frequently used technical process for themodification of polymers and their properties.

In order to obtain a grafted (co)polymer, reactive extrusion is usuallycarried out by extruding a (co)polymer, an ethylenically unsaturatedcompound and a peroxide as radical generator. According to the type ofmodification (e.g. with maleic acid anhydride, glycidylmethylmethacrylate or vinylsilanes) the resulting polymers are used ascompatibilizers, adhesives or surface-modifiers. This is for exampledescribed in Reactive Modifiers for Polymers, edited by S. Al-Malalka,Chapman & Hall, 1997 chapter 1 pages 1-97. The processes are mainlybased on peroxides as radical generators. These prior art processes showsevere disadvantages, such as side reactions, which influence theprocessing performance (polymer degradation, crosslinking/gel formation)or loss of long term thermal stability of the polymer by residualperoxides or their reaction products. Safety aspects with regard to theprocessing of plastic materials with peroxides are an additional issue.

Graft copolymers with oligomeric or polymeric side chains are difficultto access by usual grafting processes. A possible method is described inWO 00/14134 and WO 00/14135. Wherein in a two-stage process “initiationpoints” are firstly generated on a polymer and subsequently controlledpolymerization reaction is carried out starting from the initiationpoints. However, it is difficult to attach high numbers of side chainsby this method.

The present invention provides a method for the preparation ofwell-defined, easily accessible comb polymer structures via condensationreactions between functional groups on the polymer backbone (e.g.polypropylene-graft maleic acid anhydride) with mono-functionalizedoligomers/polymers. The process of the instant invention can be carriedout by reactive extrusion and is excellently suitable for large-scaleindustrial processes.

It has been found that by grafting epoxy-functionalizedNO-terminated-oligomers/polymers, prepared by controlled free radicalpolymerization (CFRP) on polymers containing groups capable to reactwith epoxides (e.g. maleic acid anhydride, MAA), comb copolymers can beprepared having the desired material properties. Because of the lowpolydispersity of the epoxy-functionalizedNO-terminated-oligomers/polymers the side chains of the resulting combpolymers are well-defined leading to improved material properties. Theepoxy-functionalized NO-terminated-oligomer/polymer is grafted via acoupling reaction of the epoxy-group with the functional group (e.g.MAA) on the polymer backbone.

One aspect of the invention is a method for the preparation of a combcopolymer comprising the steps

a) polymerizing an ethylenically unsaturated monomer to a oligomer,cooligomer, polymer or copolymer in the presence of aninitiator/regulator of formula (I)

-   -   wherein L is a linking group selected from the group consisting        of C₁-C₁₈alkylene, phenylene, C₁-C₁₈alkylene-oxy substituted        with a phenyl group, phenylene-C₁-C₁₈alkylene,        C₁-C₁₈alkylene-phenylene, C₁-C₁₈alkylene-phenylene-oxy and        C₅-C₁₂cycloalkylene;    -   R_(p) and R_(q) are independently tertiary bound C₄-C₂₆alkyl        groups or C₃-C₁₇ secondary bound alkyl groups which are        unsubstituted or substitituted by one or more electron        withdrawing groups or by phenyl; or    -   R_(p) and R_(q) together form a 5, 6 or 7 membered heterocyclic        ring which is substituted at least by 4 C₁-C₄alkyl groups and        which may be interrupted by a further nitrogen or oxygen atom;        and in a second step        b) reacting the polymer or copolymer prepared under a) together        with a random, block or graft copolymer, having attached a        functional group X selected from the group consisting of

or having a group X

as repetitive unit in the backbone wherein R′ is C₁-C₁₈alkyl;in the melt in an apparatus suitable for mixing a polymer melt.

Examples for C₁-C₁₈alkylene-oxy substituted with a phenyl group are thegroups

C₁-C₁₈alkylene-phenylene-oxy is for example

wherein R″ and R′″ are independently hydrogen or C₁-C₈alkyl, which maybe linear or branched. The oxy substitution is preferably in the paraposition.

C₅-C₁₂cycloalkylene is typically cyclopentyl or cyclohexyl.

R_(p) and R_(q) together with the nitrogen atom to which they are bondedform for example a 5, 6 or 7 membered heterocyclic ring which issubstituted at least by 4 C₁-C₄alkyl groups and which may be interruptedby a further nitrogen or oxygen atom. Preference is given to 6 memberedheterocyclic rings, in particular to piperidine rings.

The ethylenically unsaturated monomer of step a) can be chosen from avariety of monomers. Such as isoprene, 1,3-butadiene, α-C₅-C₁₈alkene,styrene, α-methyl styrene, p-methyl styrene p-tert-butyl-styrene or acompound of formula CH₂═C(R_(a))—(C=Z)-R_(b), wherein R_(a) is hydrogenor C₁-C₄alkyl, R_(b) is NH₂, O⁻(Me⁺), unsubstituted C₁-C₁₈alkoxy,C₂-C₁₀₀alkoxy, interrupted by at least one N and/or O atom, orhydroxy-substituted C₁-C₁₈alkoxy, unsubstituted C₁-C₁₈alkylamino,di(C₁-C₁₈alkyl)amino, hydroxy-substituted C₁-C₁₈alkylamino orhydroxy-substituted di(C₁-C₁₈alkyl)amino, —O—CH₂—CH₂—N(CH₃)₂ or—O—CH₂—CH₂—N⁺H(CH₃)₂An⁻;

-   An⁻ is a anion of a monovalent organic or inorganic acid;-   Me is a monovalent metal atom or the ammonium ion.-   Z is oxygen or sulfur.

Examples for R_(a) as C₂-C₁₀₀alkoxy interrupted by at least one O atomare of formula

wherein R_(c) is C₁-C₂₅alkyl, phenyl or phenyl substituted byC₁-C₁₈alkyl, R_(d) is hydrogen or methyl and v is a number from 1 to 50.These monomers are for example derived from non ionic surfactants byacrylation of the corresponding alkoxylated alcohols or phenols. Therepeating units may be derived from ethylene oxide, propylene oxide ormixtures of both.

Further examples of suitable acrylate or methacrylate monomers are givenbelow.

and R_(a) have the meaning as defined above and R_(e) is methyl, benzylor benzoylbenzyl. An⁻ is preferably Cl⁻, Br⁻ or ⁻O₃S—O—CH₃.

Preferably R_(a) is hydrogen or methyl, R_(b) is NH₂, gycidyl,unsubstituted or with hydroxy substituted C₁-C₄alkoxy, unsubstitutedC₁-C₄alkylamino, di(C₁-C₄alkyl)amino, hydroxy-substitutedC₁-C₄alkylamino or hydroxy-substituted di(C₁-C₄alkyl)amino; and

-   Z is oxygen.

The ethylenically unsaturated monomer of step a) is for example selectedfrom the group consisting of styrene, substituted styrene, conjugateddienes, vinyl acetate, vinylpyridine, vinylpyrrolidone, vinylimidazole,maleic anhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acidsalts, (alkyl)acrylic esters, (meth)acrylonitriles, (alkyl)acrylamides,vinyl halides and vinylidene halides.

For instance the ethylenically unsaturated monomer is styrene,substituted styrene, methylacrylate, ethylacrylate, butylacrylate,isobutylacrylate, tert. butylacrylate, hydroxyethylacrylate,hydroxypropylacrylate, dimethylaminoethylacrylate, methyl(meth)acrylate,ethyl(meth)acrylate, butyl(meth)acrylate, hydroxyethyl(meth)acrylate,hydroxypropyl(meth) acrylate, dimethylaminoethyl(meth)acrylate,acrylonitrile, methacrylonitrile, acrylamide, methacrylamide ordimethylaminopropyl-methacrylamide.

Very suitable monomers are for example styrene, C₁-C₈alkylesters ofacrylic or methacrylic acid, such as n-butylacrylate or methacrylate,acrylonitrile or methacrylonitrile, in particular styrene, acrylonitrileand n-butylacrylate.

It is also possible to use mixtures of the afore mentioned monomers, inparticular styrene/acrylonitrile, styrene/butylacrylate,styrene/methylmethacrylate and styrene/butyl-methacrylate.

In a specific embodiment of the invention the initiator/regulator is offormula (IIa)

-   R₁, R₂, R₃ and R₄ are independently of each other C₁-C₄alkyl;-   R₅ is hydrogen or C₁-C₄alkyl;-   R′₆ is hydrogen and R₆ is H, OR₁₀, NR₁₀R₁₁, —O—C(O)—R₁₀ or    NR₁₁—C(O)—R_(10;)-   R₁₀ and R₁₁ independently are hydrogen, C₁-C₁₈alkyl, C₂-C₁₈alkenyl,    C₂-C₁₈alkinyl or C₂-C₁₈alkyl which is substituted by at least one    hydroxy group or, if R₆ is NR₁₀R₁₁, taken together, form a    C₂-C₁₂alkylene bridge or a C₂-C₁₂-alkylene bridge interrupted by at    least one O atom; or-   R₆ and R′₆ together are both hydrogen, a group ═O or ═N—O—R₂₀    wherein-   R₂₀ is H, straight or branched C₁-C₁₈alkyl, C₃-C₁₈alkenyl or    C₃-C₁₈alkinyl, which may be unsubstituted or substituted, by one or    more OH, C₁-C₈ alkoxy, carboxy, C₁-C₈alkoxycarbonyl;-   C₅-C₁₂cycloalkyl or C₅-C₁₂cycloalkenyl;-   phenyl, C₇-C₉phenylalkyl or naphthyl which may be unsubstituted or    substituted by one or more C₁-C₈alkyl, halogen, OH, C₁-C₈alkoxy,    carboxy, C₁-C₈alkoxycarbonyl;-   —C(O)—C₁-C₃₈alkyl, or an acyl moiety of a α,β-unsaturated carboxylic    acid having 3 to 5 carbon atoms or of an aromatic carboxylic acid    having 7 to 15 carbon atoms;-   —SO₃ ⁻Q⁺, —PO(O⁻Q⁺)₂, —P(O)(OR₂)₂, —SO₂—R₂, —CO—NH—R₂, —CONH₂,    COOR₂, or Si(Me)₃, wherein Q⁺ is H⁺, ammonium or an alkali metal    cation; or-   R₆ and R₆′ are independently —O—C₁-C₁₂alkyl, —O—C₁-C₁₂alkenyl,    —O—C₃-C₁₂alkinyl, —O—C₅-C₈cycloalkyl, —O-phenyl, —O-naphthyl,    —O—C₇-C₉phenylalkyl; or-   R₆ and R′₆ together form one of the bivalent groups    —O—C(R₂₁)(R₂₂)—CH(R₂₃)—O—, —O—CH(R₂₁)—CH₂₂-C(R₂₂)(R₂₃)—O—,    —O—CH(R₂₂)—CH₂-C(R₂₁)(R₂₃)—O—, —O—CH₂ -C(R₂₁)(R₂₂)—CH(R₂₃)—O—,    —O—o—phenylene—O—, —O-1,2-cyclohexyliden-O—,

-   R₂₁ is hydrogen, C₁-C₁₂alkyl, COOH, COO—(C₁-C₁₂)alkyl or CH₂OR₂₄;-   R₂₂ and R₂₃ are independently hydrogen, methyl ethyl, COOH or    COO—(C₁-C₁₂)alkyl;-   R₂₄ is hydrogen, C₁-C₁₂alkyl, benzyl or a monovalent acyl residue    derived from an aliphatic, cycloaliphatic or aromatic monocarboxylic    acid having up to 18 carbon atoms; and-   R₇ and R₈ are independently hydrogen or C₁-C₁₈alkyl.

C₁-C₁₈alkyl can be linear or branched. Examples are methyl, ethyl,propyl, isopropyl, butyl, 2-butyl, isobutyl, t-butyl, pentyl, 2-pentyl,hexyl, heptyl, octyl, 2-ethylhexyl, t-octyl, nonyl, decyl, undecyl,dodecyl or octadecyl. Where up to C₃₆alkyl is possible, C₁-C₁₈alkyl ispreferred.

Alkyl substituted by a group —COOH is for example CH₂—COOH,CH₂—CH₂—COOH, (CH₂)₃—COOH or CH₂—CHCOOH—CH₂—CH₃

Hydroxyl- or alkoxycarbonyl substituted C₁-C₁₈alkyl can be, for example,2-hydroxyethyl, 2-hydroxypropyl, methoxycarbonylmethyl or2-ethoxycarbonylethyl.

Alkenyl having from 2 to 18 carbon atoms is a branched or unbranchedradical, for example propenyl, 2-butenyl, 3-butenyl, isobutenyl,n-2,4-pentadienyl, 3-methyl-2butenyl, n-2-octenyl, n-2-dodecenyl,isododecenyl.

Alkinyl having from 2 to 18 carbon atoms is a branched or unbranchedradical, for example propinyl, 2-butinyl, 3-butinyl, isobutinyl,n-2,4-pentadiinyl, 3-methyl-2-butinyl, n-2-octinyl, n-2-dodecinyl,isododecinyl.

Examples of alkoxy are methoxy, ethoxy, propoxy, isopropoxy, butoxy,isobutoxy, pentoxy, isopentoxy, hexoxy, heptoxy or octoxy.

C₇-C₉phenylalkyl is for example benzyl, α-methylbenzyl,α,α-dimethylbenzyl or 2-phenylethyl, benzyl is preferred.

C₅-C₁₂cycloalkyl is for example cyclopentyl, cyclohexyl, cycloheptyl,methylcyclopentyl or cyclooctyl.

C₅-C₁₂cycloalkenyl is for example 3-cyclopentenyl, 3-cyclohexenyl or3-cycloheptenyl.

Examples of a monocarboxylic acid having up to 18 carbon atoms areformic acid, acetic acid, propionic acid, the isomers of valeric acid,methyl ethyl acetic acid, trimethyl acetic acid, capronic acid, lauricacid or stearic acid. Examples for unsaturated aliphatic acids areacrylic acid, methacrylic acid, crotonic acid, linolic acid and oleicacid.

Typical examples of cycloaliphatic carboxylic acids are cyclohexanecarboxylic acid or cyclopentane carboxylic acid.

Examples of aromatic carboxylic acids are benzoic acid, salicylic acidor cinnamic acid.

Halogen is F, Cl, Br or I.

C₁-C₁₈alkylene is a branched or unbranched radical, for examplemethylene, ethylene, propylene, trimethylene, tetramethylene,pentamethylene, hexamethylene, heptamethylene, octamethylene,decamethylene or dodecamethylene.

C₂-C₁₂alkylene bridges interrupted by at least one O atom are, forexample, —CH₂—O—CH₂—CH₂, —CH₂—O—CH₂—CH₂—CH₂, —CH₂—O—CH₂—CH₂—CH₂—,—CH₂—O—CH₂—CH₂—O—CH₂—.

Alkoxycarbonyl is for example methoxycarbonyl, ethoxycarbonyl orpropoxycarbonyl.

For example R₁, R₂, R₃, R₄ are methyl, or R₁ and R₃ are ethyl and R₂ andR₄ are meth and R₂ are ethyl and R₃ and R₄ are methyl.

For instance R₅ is hydrogen or methyl.

In a specific embodiment of the invention R′₆ is hydrogen and R₆ is H,OR₁₀, NR₁₀R₁₁, —O—C(O)—R₁₀ or NR₁₁—C(O)—R₁₀;

R₁₀ and R₁₁ independently are hydrogen, C₁-C₁₈alkyl, C₂-C₁₈alkenyl,C₂-C₁₈alkinyl or C₂-C₁₈alkyl which is substituted by at least onehydroxy group or, if R₆ is NR₁₀R₁₁, taken together, form aC₂-C₁₂alkylene bridge or a C₂-C₁₂alkylene bridge interrupted by at leastone O atom; or

-   R₆ and R′₆ together are both hydrogen, a group ═O or ═N—O—R₂₀    wherein-   R₂₀ is H or straight or branched C₁-C₁₈alkyl.

In particular R₆ and R′₆ together form one of the bivalent groups—O—C(R₂₁)(R₂₂)—CH(R₂₃)—O —,—O—CH(R₂₁)—CH₂₂—C(R₂₂)(R₂₃)—O—,—O—CH(R₂₂)CH₂—C(R₂₁)(R₂₃)—O—, —O—CH₂—C(R₂₁)(R₂₂)—CH(R₂₃)—O— and R₂₁, R₂₂and R₂₃ have the meaning as defined above.

In another embodiment of the invention the initiator/regulator is offormula (IIb)

Specific compounds are given in Table A

TABLE A Compound Number Structure 101

102

103

104

105

The compounds of formula IIa and IIb and in particular the compoundsgiven in Table A are known and may be prepared as described in WO99/46261, WO 02/48109, U.S. Pat. No. 5,721,320 or WO97/36944.

Further nitroxyl radicals are principally known from U.S. Pat. No.4,581,429 or EP-A-621 878. Particularly useful are the open chaincompounds described in WO 98/13392, WO 99/03894 and WO 00/07981, thepiperidine derivatives described in WO 99/67298 and GB 2335190 or theheterocyclic compounds described in GB 2342649 and WO 96/24620.

-   Still further suitable nitroxyl radicals are described in WO 02/4805    and in WO 02/100831. These nitroxyl radicals can be reacted in    analogy to prepare the corresponding epoxy functionalized nitroxyl    ethers. Also suitable is compound (106).

The compound can be prepared according to WO 96/24620 and functionalizedwith the epoxy group as described for example in WO 02/48109.

The radical polymerization process of step a) is known and may becarried out in bulk, in the presence of an organic solvent or in thepresence of water or in mixtures of organic solvents and water.Additional cosolvents or surfactants, such as glycols or ammonium saltsof fatty acids, may be present. Other suitable cosolvents are describedhereinafter.

If organic solvents are used, suitable solvents or mixtures of solventsare typically pure alkanes (hexane, heptane, octane, isooctane),aromatic hydrocarbons (benzene, toluene, xylene), halogenatedhydrocarbons (chlorobenzene), alkanols (methanol, ethanol, ethyleneglycol, ethylene glycol monomethyl ether), esters (ethyl acetate,propyl, butyl or hexyl acetate) and ethers (diethyl ether, dibutylether, ethylene glycol dimethyl ether), anisol, tert-butyl-benzene ormixtures thereof.

Preferably the compound of formula (IIa) or (IIb) is present in anamount of 0.001 mol-% to 20 mol-%, based on the monomer or monomermixture. When monomer mixtures are used, mol-% is calculated on anaverage molecular weight.

An additional source of free radicals may also be added. The source offree radicals is for example a bis-azo compound, a peroxide, perester ora hydroperoxide.

Scission of the O—C bond of the nitroxylether may be effected byultrasonic treatment, radiation with actinic light or heating.

The scission of the O—C bond is preferably effected by heating and takesplace at a temperature of between 50° C. and 180° C., more preferablyfrom 90° C. to 150° C.

The polymerization reaction is usually carried out under atmosphericpressure.

After the polymerization is completed or the intended monomer conversionis achieved, the polymer is isolated by removing the solvent and/orresidual monomer by distillation, stripping with water or precipitation.

The oligomer, cooligomer, polymer or copolymer of step a) has forexample a polydispersity (M_(W)/M_(N)) between 1.0 and 2.5, inparticular between 1.1 and 2.0.

The oligomer, cooligomer, polymer or copolymer of step a) preferably hasa number molecular weight average from 800 to 100000, more preferablyfrom 1000 to 30 000 Daltons.

The oligomer, cooligomer, polymer or copolymer of step a) is stableafter isolation at room temperature and can be stored for several monthsbefore being used in step b). It is however also possible to carry outreaction step b) directly after step a).

The polymer of step b) can be choosen from a variety of polymers, whichare modified with the reactive groups —COOH, NH₂, —NHR′, —C(O)—NHR′,

either by conventional graft reaction or by copolymerization having thenfor example a group

as repetitive unit in the backbone. Polymers, which can be modified withthe reactive group are mentioned below.

-   1. Polymers of monoolefins and diolefins, for example polypropylene,    polyisobutylene, polybut-1-ene, poly-4-methylpent-1-ene,    polyvinylcyclohexane, polyisoprene or polybutadiene, as well as    polymers of cycloolefins, for instance of cyclopentene or    norbornene, polyethylene (which optionally can be crosslinked), for    example high density polyethylene (HDPE), high density and high    molecular weight polyethylene (HDPE-HMW), high density and ultrahigh    molecular weight polyethylene (HDPE-UHMW), medium density    polyethylene (MDPE), low density polyethylene (LDPE), linear low    density polyethylene (LLDPE), (VLDPE) and (ULDPE).

Polyolefins, i.e. the polymers of monoolefins exemplified in thepreceding paragraph, preferably polyethylene and polypropylene, can beprepared by different, and especially by the following, methods:

-   -   a) radical polymerisation (normally under high pressure and at        elevated temperature).    -   b) catalytic polymerization using a catalyst that normally        contains one or more than one metal of groups IVb, Vb, VIb or        VIII of the Periodic Table. These metals usually have one or        more than one ligand, typically oxides, halides, alcoholates,        esters, ethers, amines, alkyls, alkenyls and/or aryls that may        be either π- or σ-coordinated. These metal complexes may be in        the free form or fixed on substrates, typically on activated        magnesium chloride, titanium(III) chloride, alumina or silicon        oxide. These catalysts may be soluble or insoluble in the        polymerisation medium. The catalysts can be used by themselves        in the polymerisation or further activators may be used,        typically metal alkyls, metal hydrides, metal alkyl halides,        metal alkyl oxides or metal alkyloxanes, said metals being        elements of groups Ia, IIa and/or IIIa of the Periodic Table.        The activators may be modified conveniently with further ester,        ether, amine or silyl ether groups. These catalyst systems are        usually termed Phillips, Standard Oil Indiana, Ziegler (-Natta),        TNZ (DuPont), metallocene or single site catalysts (SSC).

-   2. Mixtures of the polymers mentioned under 1), for example mixtures    of polypropylene with polyisobutylene, polypropylene with    polyethylene (for example PP/HDPE, PP/LDPE) and mixtures of    different types of polyethylene (for example LDPE/HDPE).

-   3. Copolymers of monoolefins and diolefins with each other or with    other vinyl monomers, for example ethylene/propylene copolymers,    linear low density polyethylene (LLDPE) and mixtures thereof with    low density polyethylene (LDPE), propylene/but-1-ene copolymers,    propylene/isobutylene copolymers, ethylene/but-1-ene copolymers,    ethylene/hexene copolymers, ethylene/methylpentene copolymers,    ethylene/heptene copolymers, ethylene/octene copolymers,    ethylene/vinylcyclohexane copolymers, ethylene/cycloolefin    copolymers (e.g. ethylene/norbornene like COC), ethylene/1-olefins    copolymers, where the 1-olefin is gene-rated in-situ;    propylene/butadiene copolymers, isobutylene/isoprene copolymers,    ethylene/vinylcyclohexene copolymers, ethylene/alkyl acrylate    copolymers, ethylene/alkyl methacrylate copolymers, ethylene/vinyl    acetate copolymers or ethylene/acrylic acid copolymers and their    salts (ionomers) as well as terpolymers of ethylene with propylene    and a diene such as hexadiene, dicyclopentadiene or    ethylidene-norbornene; and mixtures of such copolymers with one    another and with polymers mentioned in 1) above, for example    polypropylene/ethylene-propylene copolymers, LDPE/ethylene-vinyl    acetate copolymers (EVA), LDPE/ethylene-acrylic acid copolymers    (EAA), LLDPE/EVA, LLDPE/EAA and alternating or random    polyalkylene/carbon monoxide copolymers and mixtures thereof with    other polymers, for example polyamides.

-   4. Hydrocarbon resins (for example C₅-C₉) including hydrogenated    modifications thereof (e.g. tackifiers) and mixtures of    polyalkylenes and starch.

Homopolymers and copolymers from 1.)-4.) may have any stereostructureincluding syndiotactic, isotactic, hemi-isotactic or atactic; whereatactic polymers are preferred. Stereoblock polymers are also included.

-   5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene).-   6. Aromatic homopolymers and copolymers derived from vinyl aromatic    monomers including styrene, α-methylstyrene, all isomers of vinyl    toluene, especially p-vinyltoluene, all isomers of ethyl styrene,    propyl styrene, vinyl biphenyl, vinyl naphthalene, and vinyl    anthracene, and mixtures thereof. Homopolymers and copolymers may    have any stereostructure including syndiotactic, isotactic,    hemi-isotactic or atactic; where atactic polymers are preferred.    Stereoblock polymers are also included.-   6a. Copolymers including aforementioned vinyl aromatic monomers and    comonomers selected from ethylene, propylene, dienes, nitrites,    acids, maleic anhydrides, maleimides, vinyl acetate and vinyl    chloride or acrylic derivatives and mixtures thereof, for example    styrene/butadiene, styrene/acrylonitrile, styrene/ethylene    (interpolymers), styrene/alkyl methacrylate, styrene/butadiene/alkyl    acrylate, styrene/butadiene/alkyl methacrylate, styrene/maleic    anhydride, styrene/acrylonitrile/methyl acrylate; mixtures of high    impact strength of styrene copolymers and another polymer, for    example a polyacrylate, a diene polymer or an    ethylene/propylene/diene terpolymer; and block copolymers of styrene    such as styrene/butadiene/styrene, styrene/isoprene/styrene,    styrene/ethylene/butylene/styrene or    styrene/ethylene/propylene/styrene.-   6b. Hydrogenated aromatic polymers derived from hydrogenation of    polymers mentioned under 6.), especially including    polycyclohexylethylene (PCHE) prepared by hydrogenating atactic    polystyrene, often referred to as polyvinylcyclohexane (PVCH).-   6c. Hydrogenated aromatic polymers derived from hydrogenation of    polymers mentioned under 6a.).-   Homopolymers and copolymers may have any stereostructure including    syndiotactic, isotactic, hemi-isotactic or atactic; where atactic    polymers are preferred. Stereoblock polymers are also included.-   7. Graft copolymers of vinyl aromatic monomers such as styrene or    α-methylstyrene, for example styrene on polybutadiene, styrene on    polybutadiene-styrene or polybutadiene-acrylonitrile copolymers;    styrene and acrylonitrile (or methacrylonitrile) on polybutadiene;    styrene, acrylonitrile and methyl methacrylate on polybutadiene;    styrene and maleic anhydride on polybutadiene; styrene,    acrylonitrile and maleic anhydride or maleimide on polybutadiene;    styrene and maleimide on polybutadiene; styrene and alkyl acrylates    or methacrylates on polybutadiene; styrene and acrylonitrile on    ethylene/propylene/diene terpolymers; styrene and acrylonitrile on    polyalkyl acrylates or polyalkyl methacrylates, styrene and    acrylonitrile on acrylate/butadiene copolymers, as well as mixtures    thereof with the copolymers listed under 6), for example the    copolymer mixtures known as ABS, MBS, ASA or AES polymers.-   8. Halogen-containing polymers such as polychloroprene, chlorinated    rubbers, chlorinated and brominated copolymer of    isobutylene-isoprene (halobutyl rubber), chlorinated or    sulfo-chlorinated polyethylene, copolymers of ethylene and    chlorinated ethylene, epichlorohydrin homo- and copolymers,    especially polymers of halogen-containing vinyl compounds, for    example polyvinyl chloride, polyvinylidene chloride, polyvinyl    fluoride, polyvinylidene fluoride, as well as copolymers thereof    such as vinyl chloride/vinylidene chloride, vinyl chloride/vinyl    acetate or vinylidene chloride/vinyl acetate copolymers.-   9. Polymers derived from α,β-unsaturated acids and derivatives    thereof such as polyacrylates and polymethacrylates; polymethyl    methacrylates, polyacrylamides and polyacrylonitriles,    impact-modified with butyl acrylate.-   10. Copolymers of the monomers mentioned under 9) with each other or    with other unsaturated monomers, for example acrylonitrile/butadiene    copolymers, acrylonitrile/alkyl acrylate copolymers,    acrylonitrile/alkoxyalkyl acrylate or acrylonitrile/vinyl halide    copolymers or acrylonitrile/alkyl methacrylate/butadiene    terpolymers.-   11. Polymers derived from unsaturated alcohols and amines or the    acyl derivatives or acetals thereof, for example polyvinyl alcohol,    polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl    maleate, polyvinyl butyral, polyallyl phthalate or polyallyl    melamine; as well as their copolymers with olefins mentioned in 1)    above.-   12. Homopolymers and copolymers of cyclic ethers such as    polyalkylene glycols, polyethylene oxide, polypropylene oxide or    copolymers thereof with bisglycidyl ethers.-   13. Polyacetals such as polyoxymethylene and those polyoxymethylenes    which contain ethylene oxide as a comonomer; polyacetals modified    with thermoplastic polyurethanes, acrylates or MBS.-   14. Polyphenylene oxides and sulfides, and mixtures of polyphenylene    oxides with styrene polymers or polyamides.-   15. Polyurethanes derived from hydroxyl-terminated polyethers,    polyesters or polybutadienes on the one hand and aliphatic or    aromatic polyisocyanates on the other, as well as precursors    thereof.-   16. Polyamides and copolyamides derived from diamines and    dicarboxylic acids and/or from aminocarboxylic acids or the    corresponding lactams, for example polyamide 4, polyamide 6,    polyamide 6/6, 6/10, 6/9, 6/12, 4/6, 12/12, polyamide 11, polyamide    12, aromatic polyamides starting from m-xylene diamine and adipic    acid; polyamides prepared from hexamethylenediamine and isophthalic    or/and terephthalic acid and with or without an elastomer as    modifier, for example poly-2,4,4,-trimethylhexamethylene    terephthalamide or poly-m-phenylene isophthalamide; and also block    copolymers of the aforementioned polyamides with polyolefins, olefin    copolymers, ionomers or chemically bonded or grafted elastomers; or    with polyethers, e.g. with polyethylene glycol, polypropylene glycol    or polytetramethylene glycol; as well as polyamides or copolyamides    modified with EPDM or ABS; and polyamides condensed during    processing (RIM polyamide systems).-   17. Polyureas, polyimides, polyamide-imides, polyetherimids,    polyesterimids, polyhydantoins and polybenzimidazoles.-   18. Polyesters derived from dicarboxylic acids and diols and/or from    hydroxycarboxylic acids or the corresponding lactones, for example    polyethylene terephthalate, polybutylene terephthalate,    poly-1,4-dimethylolcyclohexane terephthalate, polyalkylene    naphthalate (PAN) and polyhydroxybenzoates, as well as block    copolyether esters derived from hydroxyl-terminated polyethers; and    also polyesters modified with polycarbonates or MBS.-   19. Polycarbonates and polyester carbonates.-   20. Polyketones.-   21. Polysulfones, polyether sulfones and polyether ketones.-   22. Natural polymers such as cellulose, rubber, gelatin and    chemically modified homologous derivatives thereof, for example    cellulose acetates, cellulose propionates and cellulose butyrates,    or the cellulose ethers such as methyl cellulose; as well as rosins    and their derivatives.-   23. Blends of the aforementioned polymers (polyblends), for example    PP/EPDM, Polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS, PC/ABS,    PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates, POM/thermoplastic    PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS, PPO/HIPS, PPO/PA    6.6 and copolymers, PA/HDPE, PA/PP, PA/PPO, PBT/PC/ABS or    PBT/PET/PC. In the case of blends, it is sufficient if only one    component is modified with the reactive group.

In a preferred embodiment the copolymer of step b) is a graftedcopolymer having the functional groups X in the graft structure.

For example the copolymer of step b) is selected from the groupconsisting of poylpropylene(PP)-graft(g)-maleic acid anhydride(MAA),ethylene-propylene-dien monomer(EPDM)-g-MAA, polyethylene(PE)-g-MAA,high density polyethylene(HDPE)-g-MAA, PP-g-acrylic acid(AA), linear lowdensity polyethylene(LLDPE)-g-MAA, PE-co-PEA-g-MAA,PE-co-polyvinylacetate(PVA)-g-MAA, PE-co-PP-g-MAA,polystyrene(PS)-co-hydrogenated polyisoprene-g-MAA,polystyrene-co-polybutadiene(PS)-g-MAA,PS-co-PE/polybutylene-co-PS-g-MAA, polyethylene(PE)-g-acrylic acid,polypropylene(PP)-g-acrylic acid, polystyrene(PS)-co-maleic acidanhydride(MAA) (alternating copolymer) andaminoethylacrylate-co-polystyrene(PS).

In particular the copolymer of step b) is PP-g-MAA or EPDM-g-MAA.

The above mentioned polymers are known and to a great extent items ofcommerce. Examples of commercially available polymers are the following:

-   -   Exxelor® PO 1020 (PP-g-MAA, Exxon)    -   Exxelor® VA 1803 (EPDM-g-MAA, Exxon)    -   Septon® KL-01 M2 (Diblockcopolymer PS-co-hydrogenated        polyisoprene-g-MMA, Kuraray)    -   Kraton® FG 1901 X (Triblockcopolymer PS-co-PE/Polybutylene        PS-g-MAA)    -   Polybond® 3009 (HDPE-9-MAA, Crompton Corp.)    -   Polybond® 1001 (PP-g-AA, Crompton Corp.)    -   Royaltuf® 465 A (EPDM-g-MAA, Uniroyal)    -   Fusabond® MF416D (Diblockcopolymer PE-co-PP-g-MAA, Du Pont)    -   Fusabond® MB-226D (LLDPE-g-MAA, Du Pont)    -   Lotader® (PE-co-PEA-g-MAA(GMA), Atofina)    -   Nucrel® (PE-g-MAA, Dupont)    -   Orevac® (PE-co-PVA-g-MAA, Atofina)

-   Admer® (PE-co-PVA-g-MMA Mitsul Petroch.)

Very suitable commercial copolymers are for example Exxelor® PO 1020(PP-g-MAA, Exxon) and Exxelor® VA 1803 (EPDM-g-MAA, Exxon).

The polymer or copolymer of step a) is added to the copolymer of step b)for example in an amount of from 0.1% to 100% by weight based on theweight of of the copolymer of step b).

Step b) of the process may be performed in any reactor suitable formixing a polymer melt. For instance the apparatus suitable for mixing apolymer melt is a mixer, kneader or extruder.

Preferably the reactor is an extruder or kneading apparatus as forexample described in “Handbuch der Kunststoffextrusion” Vol. I, editorF. Hensen, W. Knappe and H. Potente, 1989, pages 3-7. If an extruder isused the process may be described as reactive extrusion process. Theremay be used single screw extruders, contrarotating and corotatingtwin-screw extruders, planetary-gear extruders, ring extruders orcokneaders. It is also possible to use processing machines provided withat least one gas removal compartment to which a vacuum can be applied.

Examples of reactiv extrusion equipment and processes are given by G. H.Hu et al., in “Reactive Modifiers for Polymers”, first edition, BlackieAcademic & Professional an Imprint of Chapman & Hall, London 1997,chapter 1, pages 1-97.

For instance, if an extruder is used, a reduced pressure of less than200 mbar is applied during extrusion. Volatile by products are removedthereby.

Alternatively the reaction can be performed in a suitable solvent, whichis able to solve at least partly the polymer of step b). Suitablesolvents are e.g. toluene, decaline for PP-g-MAA, chloro- ordichlorobenzene for SBS-g-MAA.

The processing temperature and reaction time depend on polymer type andepoxy-terminated functionalized NO-oligomers/polymers. The temperatureis generally above the softening point of the polymers/oligomers tocreate a well processible and homogeneous melt. The reaction time isselected to achieve maximum grafting yield. Typical reaction times arefrom a few minutes to an hour. Preferably the reaction time is from 1min to 1 h, most preferably from 2 min to 20 min.

Typically the processing temperature of step b) is between 150° C. and250° C.

A further aspect of the invention is a composition comprising a polymeror copolymer prepared by polymerizing at least one ethylenicallyunsaturated monomer in the presence of an initiator/regulator of formula(I) as defined above and a random, block or graft copolymer, havingattached a functional group X selected from the group consisting of

—COOH, —NH₂, —NHR′, —C(O)—NHR′,

or having a group X

as repetitive unit in the backbone.

Also an aspect of the invention is a comb copolymer obtainable by themethod described above.

The invention also comprises a polymer of formula (III)

wherein

-   A and D are repeating units derived from at least one ethylenically    unsaturated monomer;-   a is a number from 1 to 100;-   d is a number from 1 to 100;-   n is a number from 1 to 1000;-   Z₁ is the reaction product of the group X, defined in claim 1 with    the epoxide group of the polymer defined in step a) of claim 1;-   W is the repeating unit of the polymer defined in step a) of claim    1;-   m is a number from 5 to 1000;-   L is a linking group selected from the group consisting of    C₁-C₁₈alkylene, phenylene, C₁-C₁₈alkylene-oxy substituted with a    phenyl group, phenylene-C₁-C₁₈alkylene, C₁-C₁₈alkylene-phenylene,    C₁-C₁₈alkylene-phenylene-oxy and C₅-C₁₂cycloalkylene; and    -   R_(p) and R_(q) are independently tertiary bound C₄-C₂₈alkyl        groups or C₃-C₁₇ secondary bound alkyl groups which are        unsubstituted or substitituted by one or more electron        withdrawing groups or by phenyl; or    -   R_(p) and R_(q) together form a 5, 6 or 7 membered heterocyclic        ring which is substituted at least by 4 C₁-C₄alkyl groups and        which may be interrupted by a further nitrogen or oxygen atom.

In particular the polymer is of formula (IIIa)

wherein R₁ to R₈ are as defined above.

For example Z₁ is a group —C(O)—O— or

which is grafted to the polymer backbone via the carbon atom.

Definitions and preferences for the individual substituents have alreadybeen given for the process of polymerization. They apply also for theother aspects of the invention.

The comb copolymers prepared by the present invention are useful forfollowing applications: adhesives, dispersants, emulsifiers,surfactants, defoamers, adhesion promoters, corrosion inhibitors,viscosity improvers, lubricants, rheology modifiers, thickeners,crosslinkers, paper treatment, water treatment, electronic materials,paints, coatings, superabsorbants, cosmetics, hair products, biocidematerials or modifiers for asphalt, leather, textiles, barriermaterials, ceramics and wood.

Consequently a further aspect of the invention is the use of a combcopolymer prepared by the method described above as dispersing agent,compatibilizer, coupling agent, barrier material, adhesive and surfaceor impact modifier.

The following examples illustrate the invention.

The following initiator/regulator compound is used for controlled freeradical polymerization (step a):3,3,8,8,10,10-hexamethyl-9-[1-(4-oxiranylmethoxy-phenyl)-ethoxy]-1,5-dioxa-9-aza-spiro[5.5]undecane(compound 103, Table A). The compound is prepared as described in WO02/48109, example A2.

A1) Synthesis of an Epoxy-Terminated Polystyrene According to step a)

Styrene is distilled under reduced pressure prior to use. In a dry,argon-purged glass vessel, 1 mol %3,3,8,8,10,10-hexamethyl-9-[1-(4-oxiranylmethoxy-phenyl)-ethoxy]-1,5-dioxa-9-aza-spiro[5.5]undecaneis dissolved in 814.1 g styrene. The solution is degassed in threeconsecutive freeze-thaw-cycles and then purged with argon. The stirredsolution is then immersed in an oil bath and polymerized at 125° C. for6 hours. After polymerization, residual monomer is removed under vacuumat 70° C. and the polymer is dried at 70° C. in a vacuum oven untilconstant weight is achieved. The number average molecular weight isdetermined by gel-permeation-chromatography (GPC) with a Hewlett PackartHP 1090 LC (column PSS 1, lengths 60 cm, elution with tetrahydrofurane(THF), rate 1 ml/min, concentration 10 mg polymer in 1 ml THF,calibration with styrene). The polydispersity is calculated from M_(n)(g/mol) and M_(w)(g/mol) as PD=M_(w)/M_(n).

-   Polymer 1=Epoxy-terminated-polystyrene (M_(n)=5900 g/mol)    -   Epoxy content>95% (determination via ¹H-NMR)        A2) Synthesis of an Epoxy-Terminated SAN According to Step a)

Styrene is distilled under reduced pressure prior to use andacrylonitrile is used undistilled. In a dry, 2 l Büchi-autoklave, 1 mol%3,3,8,8,10,10-hexamethyl-9-[1-(4-oxiranylmethoxy-phenyl)-ethoxy]-1,5-dioxa-9-aza-spiro[5.5]undecaneis dissolved in 1125 g styrene and 375 g acrylonitrile. The solution isdegassed and then purged with argon. The stirred solution is thenimmersed in an oil bath and polymerized at 110° C. for 6 hours. Afterpolymerization the polymer is precipitated in methanol and dried at 40°C. in a vacuum oven until constant weight is achieved. The numberaverage molecular weight is determined by gel-permeation-chromatography(GPC) with a Hewlett Packart HP 1090 LC (column PSS 1, lengths 60 cm,elution with tetrahydrofurane (THF), rate 1 ml/min, concentration 10 mgpolymer in 1 ml THF, calibration with styrene). The polydispersity iscalculated from M_(n) (g/mol) and M_(w) (g/mol) as PD=M_(w)/M_(n).

-   Polymer 2=Epoxy-terminated-SAN (Mn=3550 g/mol)    -   Epoxy content>95% (determination via ¹H-NMR)        A3) Synthesis of an Epoxy-Terminated PS-co-PMMA According to        Step a)

Styrene and MMA are distilled under reduced pressure prior to use. In adry, 2 l Büchi-autoklave, 1 mol %3,3,8,8,10,10-hexamethyl-9-[1-(4-oxiranylmethoxy-phenyl)-ethoxy]-1,5-dioxa-9-aza-spiro[5.5]undecaneis dissolved in 750 g (375 g for polymer 4) styrene and 750 g (1125 gfor polymer 4) MMA. The solution is degassed and then purged with argon.The stirred solution is then immersed in an oil bath and polymerized at110° C. for 6 hours. After polymerization the polymer is precipitated inmethanol and dried at 40° C. in a vacuum oven until constant weight isachieved. The number average molecular weight is determined bygel-permeation-chromatography (GPC) with a Hewlett Packart HP 1090 LC(column PSS 1, lengths 60 cm, elution with tetrahydrofurane (THF), rate1 ml/min, concentration 10 mg polymer in 1 ml THF, calibration withstyrene). The polydispersity is calculated from M_(n) (g/mol) and M_(w)(g/mol) as PD=M_(w)/M_(n).

-   Polymer 3=Epoxy-terminated-PS-co-PMMA (1:1) (M_(n)=3650 g/mol)    -   Epoxy content>95% (determination via ¹H-NMR)-   Polymer 4=Epoxy-terminated-PS-co-PMMA (1:3) (M_(n)=4610 g/mol)    -   Epoxy content>95% (determination via ¹H-NMR)        B1) B2) Grafting of polymer 1 of example A1 onto PP-g-MAA

350 g PP-G-MAA are extruded in the presence of 35 g (10%) resp. 70 g(20%) polymer 1 (see table 1) in a twin screw extruder (Haake TW 100) at150° C. and 60 rpm. The resulting polymer is strand granulated and theMFR is determined in accordance with ISO 1133. A small amount ofunreacted polymer 1 is removed by dissolving the samples in1,2-di-chlorobenzene at 130° C. The comb polymer is precipitated inmethanol and dried in a vacuum oven at 90° C.

The number average molecular weight is determined byhigh-temperature-gel-permeation-chromatography (HT-GPC) with a PolymerLaboratories PL-GPC 220 (columns waters HT2, HT3, HT4, HT5, HT6, elutionwith 1,2,4-trichlorobenzene at 140° C., injection volume 1 μl, RIdetection, calibration with 10 polystyrene-standards from PolymerLaboratories (molecular weight array 580-7,5*10⁶), software: PSS WINGPCV. 6.02)). The polydispersity is calculated from M_(n) (g/mol) and M_(w)(g/mol) as PD=M_(w)/M_(n).

The result is shown in Table 1.

TABLE 1 Grafting of polymer 1 onto PP-g-MAA Increase Epoxy-funct. Mn ofMn Example Polymer NO-term-PS MFR [g/mol] [%] PD Reference PP-g-MAA 0 9646350 0 2.5 B1 PP-g-MAA 10% polymer 1 90 62500 34.8 2.0 B2 PP-g-MAA 20%polymer 1 95 72700 56.9 1.9 Reference: without addition of polymer 1PP-g-MAA: Exxelor PO 1020 (commercial product, Exxon) MFR: 190° C.; 1.2kgB3) B4) Grafting of Polymer 1 onto EPDM-g-MAA

350 g EPDM-g-MAA are extruded in the presence of 35 g (10%) polymer 1(see Table 2) in a twin screw extruder (Haake TW 100) at 190° C. (B3)resp. 210° C. (B4) and 50 rpm. The resulting polymer is strandgranulated and the MFR is determined in accordance with ISO 1133. Asmall amount of unreacted polymer 1 is removed by dissolving the samplesin 1,2-dichlorobenzene at 130° C. The comb polymer is precipitated inmethanol and dried in a vacuum oven at 90° C.

The number average molecular weight is determined byhigh-temperature-gel-permeation-chromatography (HT-GPC) with a PolymerLaboratories PL-GPC 220 (columns waters HT2, HT3, HT4, HT5, HT6, elutionwith 1,2,4-Trichlorobenzene at 140° C., injection volume 1 μl, RIdetection, calibration with 10 polystyrene-standards from PolymerLaboratories (molecular weight array 580-7,5*10⁶), software: PSS WINGPCV. 6.02)). The polydispersity is calculated from M_(n) (g/mol) and M_(w)(g/mol) as PD=M_(w)/M_(n).

TABLE 2 Grafting of compound 1 onto EPDM-g-MAA Increase Epoxy-funct. Mnof Mn Example Polymer NO-term-PS MFR [g/mol] [%] PD Reference EPDM-g-MAA0 40 88300 0 3.6 B3 EPDM-g-MAA 10% 63 105000 18.1 3.0 polymer 1 B4EPDM-g-MAA 10% 51 109000 23.4 3.1 polymer 1 Reference: without additionof polymer 1 EPDM-g-MM: Exxelor VA 1803 (commercial product, Exxon) MFR:200° C.; 21.6 kgB5) Grafting of Polymer 2 of Example A2 onto PP-g-MAA

350 g PP-g-MAA are extruded in the presence of 70 g (20%) polymer 2 (seetable 3) in a twin screw extruder (Haake TW 100) at 150° C. and 40 rpm.The resulting polymer is strand granulated and the MFR is determined inaccordance with ISO 1133.

The number average molecular weight is determined byhigh-temperature-gel-permeation-chromatography (HT-GPC) with a PolymerLaboratories PL-GPC 220 (columns waters HT2, HT3, HT4, HT5, HT6, elutionwith 1,2,4-trichlorobenzene at 140° C., injection volume 1 μl, RIdetection, calibration with 10 polystyrene-standards from PolymerLaboratories (molecular weight array 580-7,5*106), software: PSS WINGPCV. 6.02)). The polydispersity is calculated from M_(n) (g/mol) and M_(w)(g/mol) as PD M_(w)/M_(n).

The result is shown in Table 3.

TABLE 3 Grafting of polymer 2 onto PP-g-MAA Increase Epoxy-funct. Mn ofMn Example Polymer NO-term-PS MFR [g/mol] [%] PD Reference PP-g-MAA 0102.9 44100 0 2.8 B5 PP-g-MAA 10% 4.33 53100 20.4 2.3 polymer 2Reference: without addition of polymer 2 PP-g-MAA: Exxelor PO 1020(commercial product, Exxon) MFR: 190° C.; 1.2 kgB6) B7) Grafting of Polymer 3 and Polymer 4 of Example A3 onto PP-g-MAA

350 g PP-g-MAA are extruded in the presence of 35 g (10%) polymer 3 orpolymer 4 (see table 4) in a twin screw extruder (Haake TW 100) at 150°C. and 40 rpm. The resulting polymer is strand granulated and the MFR isdetermined in accordance with ISO 1133.

The number average molecular weight is determined byhigh-temperature-gel-permeation-chromatography (HT-GPC) with a PolymerLaboratories PL-GPC 220 (columns waters HT2, HT3, HT4, HT5, HT6, elutionwith 1,2,4-trichlorobenzene at 140° C., injection volume 1 μl, RIdetection, calibration with 10 polystyrene-standards from PolymerLaboratories (molecular weight array 580-7,5*10⁶), software: PSS WINGPCV. 6.02)). The polydispersity is calculated from M_(n) (g/mol) and M_(w)(g/mol) as PD=M_(w)/M_(n).

The result is shown in Table 4.

TABLE 4 Grafting of polymer 3 or polymer 4 onto PP-g-MAA IncreaseEpoxy-funct. Mn of Mn Example Polymer NO-term-PS MFR [g/mol] [%] PDReference PP-g-MAA 0 102.9 44100 0 2.8 B6 PP-g-MAA 10% polymer 3 56.849000 11.1 3.0 B7 PP-g-MAA 10% polymer 4 67.2 50000 13.4 3.0 Reference:without addition of polymer 3 or polymer 4 PP-g-MAA: Exxelor PO 1020(commercial product, Exxon) MFR: 190° C.; 1.2 kg

1. A method for the preparation of a comb copolymer comprising the stepsa) polymerizing an ethylenically unsaturated monomer to an oligomer,cooligomer, polymer or copolymer in the presence of aninitiator/regulator of formula (I)

wherein L is a linking group selected from the group consisting ofC₁-C₁₈alkylene, phenylene, C₁-C₁₈alkylene-oxy substituted with a phenylgroup, phenylene-C₁-C₁₈alkylene, C₁-C₁₈alkylene-phenylene,C₁-C₁₈alkylene-phenylene-oxy and C₅-C₁₂cycloalkylene; R_(p) and R_(q)are independently tertiary bound C₄-C₂₈alkyl groups or C₃-C₁₇ secondarybound alkyl groups which are unsubstituted or substitituted by one ormore electron withdrawing groups or by phenyl; or R_(p) and R_(q)together form a 5, 6 or 7 membered heterocyclic ring which issubstituted at least by 4 C₁-C₄alkyl groups and which may be interruptedby a further nitrogen or oxygen atom; and in a second step b) reactingthe oligomer, cooligomer, polymer or copolymer prepared under a)together with a grafted copolymer, which grafted copolymer functionalgroups X in the graft structure, where X is selected from the groupconsisting of —COOH, —NH₂, —NHR′, —C(O)—NHR′,

and where R′ is C₁-C₁₈alkyl, in the melt in an apparatus suitable formixing a polymer melt.
 2. A method according to claim 1 wherein theethylenically unsaturated monomer of step a) is selected from the groupconsisiting of styrene, substituted styrene, conjugated dienes, vinylacetate, vinylpyridine, vinylpyrrolidone, vinylimidazole, maleicanhydride, (alkyl)acrylic acidanhydrides, (alkyl)acrylic acid salts,(alkyl)acrylic esters, (meth)acrylonitriles, (alkyl)acrylamides, vinylhalides and vinylidene halides.
 3. A method according to claim 2 whereinin step a) the ethylenically unsaturated monomer is styrene, substitutedstyrene, methylacrylate, ethylacrylate, butylacrylate, isobutylacrylate,tert. butylacrylate, hydroxyethylacrylate, hydroxypropylacrylate,dimethylaminoethylacrylate, methyl(meth)acrylate, ethyl(meth)acrylate,butyl(meth)acrylate, hydroxyethyl(meth)acrylate,hydroxypropyl(meth)acrylate, dimethylaminoethyl(meth)acrylate,acrylonitrile, methacrylonitrile, acrylamide, methacrylamide ordimethylaminopropyl-methacrylamide.
 4. A method according to claim 1wherein the initiator/regulator is of formula (IIa)

wherein R₁, R₂, R₃ and R₄ are independently of each other C₁-C₄alkyl; R₅is hydrogen or C₁-C₄alkyl; R′₆ is hydrogen and R₆ is H, OR₁₀, NR₁₀R₁₁,—O—C(O)—R₁₀ or NR₁₁—C(O)—R₁₀; R₁₀ and R₁₁ independently are hydrogen,C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkinyl or C₂-C₁₈alkyl which issubstituted by at least one hydroxy group or, if R₆ is NR₁₀R₁₁, takentogether, form a C₂-C₁₂alkylene bridge or a C₂-C₁₂-alkylene bridgeinterrupted by at least one O atom; or R₆ and R′₆ together are bothhydrogen, a group ═O or ═N—O—R₂₀ wherein R₂₀ is H, straight or branchedC₁-C₁₈alkyl, C₃-C₁₈alkenyl or C₃-C₁₈alkinyl, which may be unsubstitutedor substituted by one or more OH, C₁-C₈alkoxy, carboxy orC₁-C₈alkoxycarbonyl; C₅-C₁₂cycloalkyl or C₅-C₁₂cycloalkenyl; phenyl,C₇-C₉phenylalkyl or naphthyl which may be unsubstituted or substitutedby one or more C₁-C₈alkyl, halogen, OH, C₁-C₈alkoxy, carboxy orC₁-C₈alkoxycarbonyl; —C(O)—C₁-C₃₆alkyl, or an acyl moiety of aα,β-unsaturated carboxylic acid having 3 to 5 carbon atoms or of anaromatic carboxylic acid having 7 to 15 carbon atoms; —SO₃ ⁻Q⁺,—PO(O⁻Q⁺)₂, —P(O)(OR₂)₂, —SO₂—R₂, —CO—NH—R₂, —CONH₂, COOR₂, or Si(Me)₃,wherein Q⁺ is H⁺, ammonium or an alkali metal cation; or R₆ and R₆′ areindependently —O—C₁-C₁₂alkyl, —O—C₃-C₁₂alkenyl, —O—C₃-C₁₂alkinyl,—O—C₅-C₈cycloalkyl, —O-phenyl, —O-naphthyl or —O—C₇-C₉phenylalkyl; or R₆and R′₆ together form one of the bivalent groups—O—C(R₂₁)(R₂₂)—CH(R₂₃)—O—, —O—CH(R₂₁)—CH₂₂—C(R₂₂)(R₂₃)—O—,—O—CH(R₂₂)—CH₂—C(R₂₁)(R₂₃)—O—, —O—CH₂—C(R ₂₁)(R₂₂)—CH(R₂₃)—O—,—O—o-phenylene-O—, —O-1,2-cyclohexyliden-O—, —O—CH₂—CH═CH—CH₂—O— or

wherein R₂₁ is hydrogen, C₁-C₁₂alkyl, COOH, COO—(C₁-C₁₂)alkyl orCH₂OR₂₄; R₂₂ and R₂₃ are independently hydrogen, methyl ethyl, COOH orCOO—(C₁-C₁₂)alkyl; R₂₄ is hydrogen, C₁-C₁₂alkyl, benzyl, or a monovalentacyl residue derived from an aliphatic, cycloaliphatic or aromaticmonocarboxylic acid having up to 18 carbon atoms; and R₇ and R₈ areindependently hydrogen or C₁-C₁₈alkyl.
 5. A method according to claim 4wherein R₁, R₂, R₃, R₄ are methyl, or R₁ and R₃ are ethyl and R₂ and R₄are methyl, or R₁ and R₂ are ethyl and R₃ and R₄ are methyl.
 6. A methodaccording to claim 4 wherein R₅ is hydrogen or methyl.
 7. A methodaccording to claim 4 wherein R′₆ is hydrogen and R₆ is H, OR₁₀, NR₁₀R₁₁,—O—C(O)—R₁₀ or NR₁₁ —C(O)—R₁₀; R₁₀ and R₁₁ independently are hydrogen,C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkinyl or C₂-C₁₈alkyl which issubstituted by at least one hydroxy group or, if R₆ is NR₁₀R₁₁, takentogether, form a C₂-C₁₂alkylene bridge or a C₂-C₁₂-alkylene bridgeinterrupted by at least one O atom; or R₆ and R′₆ together are bothhydrogen, a group ═O or ═N—O—R₂₀ wherein R₂₀ is H or straight orbranched C₁-C₁₈alkyl.
 8. A method according to claim 4 wherein R₆ andR′₆ together form one of the bivalent groups —O—C(R₂₁)(R₂₂)—CH(R₂₃)—O—,—O—CH(R₂₁)—CH₂₂—C(R₂₂)(R₂₃)—O—, —O—CH(R₂₂)—CH₂—C(R₂₁)(R₂₃)—O— or—O—CH₂—C(R₂₁)(R₂₂)—CH(R₂₃)—O—.
 9. A method according to claim 1 whereinthe initiator/regulator is of formula (IIb)

wherein R₁, R₂, R₃ and R₄ are independently of each other C₁-C₄alkyl; R₅is hydrogen or C₁-C₄alkyl; R′₆ is hydrogen and R₆ is H, OR₁₀, NR₁₀R₁₁,—O—C(O)—R₁₀ or NR₁₁—C(O)—R₁₀; R₁₀ and R₁₁ independently are hydrogen,C₁-C₁₈alkyl, C₂-C₁₈alkenyl, C₂-C₁₈alkinyl or C₂-C₁₈alkyl which issubstituted by at least one hydroxy group or, if R₆ is NR₁₀R₁₁, takentogether, form a C₂-C₁₂alkylene bridge or a C₂-C₁₂-alkylene bridgeinterrupted by at least one O atom; or R₆ and R′₆ together are bothhydrogen, a group ═O or ═N—O—R₂₀ wherein R₂₀ is H, straight or branchedC₁-C₁₈alkyl, C₃-C₁₈alkenyl or C₃-C₁₈alkinyl, which may be unsubstitutedor substituted by one or more OH, C₁-C₈alkoxy, carboxy orC₁-C₈alkoxycarbonyl; C₅-C₁₂cycloalkyl or C₅-C₁₂cycloalkenyl; phenyl,C₇-C₉phenylalkyl or naphthyl which may be unsubstituted or substitutedby one or more C₁-C₈alkyl, halogen, OH, C₁-C₈alkoxy, carboxy orC₁-C₈alkoxycarbonyl; —C(O)—C₁-C₃₆alkyl, or an acyl moiety of aα,β-unsaturated carboxylic acid having 3 to 5 carbon atoms or of anaromatic carboxylic acid having 7 to 15 carbon atoms; —SO₃ ⁻Q⁺,—PO(O⁻Q⁺)₂, —P(O)(OR₂)₂, —SO₂—R₂, —CO—NH—R₂, CONH₂, or Si(Me)₃, whereinQ⁺ is H⁺, ammonium or an alkali metal cation; or R₆ and R₆′ areindependently —O—C₁-C₁₂alkyl, —O—C₃-C₁₂alkenyl, —O—C₃-C₁₂alkinyl,—O—C₅-C₈cycloalkyl, —O-phenyl, —O-naphthyl or —O—C₇-C₉phenylalkyl; or R₆and R′₆ together form one of the bivalent groups—O—C(R₂₁)(R₂₂)—CH(R₂₃)—O—, —O—CH(R₂₁)—CH₂₂—C(R₂₂)(R₂₃)—O—,—O—CH(R₂₂)—CH₂—C(R₂₁)(R₂₃)—O—, —O—CH₂—C(R₂₁)(R₂₂)—CH(R₂₃)—O—,—O—o-phenylene-O—, —O-1,2-cyclohexyliden-O—, —O—CH₂—CH═CH—CH₂—O— or

wherein R₂₁ is hydrogen, C₁-C₁₂alkyl, COOH, COO—(C₁-C₁₂)alkyl orCH₂OR₂₄; R₂₂ and R₂₃ are independently hydrogen, methyl ethyl, COOH orCOO—(C₁-C₁₂)alkyl; R₂₄ is hydrogen, C₁-C₁₂alkyl, benzyl, or a monovalentacyl residue derived from an aliphatic, cycloaliphatic or aromaticmonocarboxylic acid having up to 18 carbon atoms; and R₇ and R₈ areindependently hydrogen or C₁-C₁₈alkyl.
 10. A method according to claim 1wherein the copolymer of step b) is selected from the group consistingof poylpropylene(PP)-graft(g)-maleic anhydride(MAA),ethylene-propylene-dien monomer(EPDM)-g-MAA, polyethylene(PE)-g-MAA,high density polyethylene(HDPE)-g-MAA, PP-g-acrylic acid(AA), linear lowdensity polyethylene(LLDPE)-g-MAA, PE-co-PEA-g-MAA,PE-co-polyvinylacetate(PVA)-g-MAA, PE-co-PP-g-MAA,polystyrene(PS)-co-hydrogenated polyisoprene-g-MAA,polystyrene-co-polybutadiene(PS)-g-MAA,PS-co-PE/polybutylene-co-PS-g-MAA, polyethylene(PE)-g-acrylic acid andpolypropylene(PP)-g-acrylic acid.
 11. A method according to claim 10wherein the copolymer of step b) is PP-g-MAA or EPDM-g-MAA.
 12. A methodaccording to claim 1 wherein the polymer or copolymer of step a) isadded to the copolymer of step b) in an amount of from 0.1% to 100% byweight based on the weight of the copolymer of step b).
 13. A methodaccording to claim 1 wherein the oligomer, cooligomer, polymer orcopolymer of step a) has a polydispersity between 1.0 and 2.5.
 14. Amethod according to claim 1 wherein the apparatus suitable for mixing apolymer melt is a mixer, kneader or extruder.
 15. A method according toclaim 1 wherein the processing temperature of step b) is between 150° C.and 250° C.